An the United States heads to the polls Tuesday for Election Day, a historic number of non-white voters could be casting their ballots. For the first time, 31 percent of eligible voters are Hispanic, black, Asian or another racial or ethnic minority, up from 29 percent in 2012, the Pew Research Center found.

About 156 million non-Hispanic whites were eligible to vote on Election Day, compared with 70 million non-white voters. The shift has been fueled by a growing Hispanic birth rate. Non-white voters represented 60 percent of the vote this year, down from 71 percent of the electorate in 2012. During that four-year period, 10.7 million more voters became eligible to cast a ballot, including 7.5 million Hispanics, blacks, Asians and other minorities. The ranks of white voters, however, only grew by 3.2 million.

It's not just that Hispanics are having more babies. Whites are dying at a higher rate. Since the 2012 presidential election, about 76 percent of all eligible voters who died, or up to 8.7 million people, were white.

Republicans, Democrats and pundits alike have described the 2016 election between Hillary Clinton and Donald Trump as a referendum on race relations in the U.S. "Donald Trump and the Twilight of White America," the Atlantic titled an article in May about the many white male voters supporting Trump. Noam Chomsky, the renowned scholar and MIT professor emeritus, told Huffington Post in February angry, low-income whites were fueling Trump's success at the polls.

“He’s evidently appealing to deep feelings of anger, fear, frustration, hopelessness, probably among sectors like those that are seeing an increase in mortality, something unheard of apart from war and catastrophe,” Chomsky said at the time.

More recently, a conservative newspaper columnist in Nevada urged voters to cast their ballots for Trump " it’s the end of America."

"Foreigners come here not out of a love for America, but for a love of the cradle-to-grave welfare state that America has become," Wayne Allyn Root wrote for the Las Vegas Review-Journal.

For whites, becoming a new minority group is an eventual possibility. Of all 16 million new eligible voters who turned 18 since the 2012 election, 57 percent were whites. But non-whites made up 43 percent of new eligible voters who recently turned 18.

Asians are also taking up a larger share of the electorate as immigrants become U.S. citizens. While 26 percent of new Hispanic voters were recently naturalized, 60 percent of new Asian eligible voters won the right to vote after becoming citizens.